Conventional head protection devices are in the form of a helmet—non-conforming, rigid head pieces lined with a Styrofoam or foam layer to protect the head from skull fractures upon direct physical contact or impact with the ground or other surface. Baseball and softball batters and runners also wear helmets to protect their heads against forces of a speeding baseball or softball, which can reach speeds up to, for example, as much as 90-100 mph for a pitched ball and 120 mph for the exit speed of a home run ball.
Just like the batters, pitchers are at significant risk for concussion-type injuries because of their proximity to the plate. Depending on the level of competition, pitchers may be within 35 feet (softball) and 60 feet (baseball) of the plate after releasing the ball. The average and fastest exit speeds of a baseball off a swung bat has been measured among the top MLB players at approximately 105 mph and 120 mph, respectively, and can hit a pitcher before the pitcher has time to react. Such an impact can impart a shockwave into the brain that causes it to rebound or if a helmet is worn, it can impart a rebound effect between the head and the helmet.